The following references are believed to represent the state of the art:    US Published Patent Application 2004/0056087 of Bonneau, JR., et al.;    US Published Patent Application 2007/0011700 of Johnson;    US Published Patent Application 2007/0078849 of Slothouber;    US Published Patent Application 2008/0191934 of Baker, et al.;    US Published Patent Application 2008/0263591 of de Heer;    PCT Published Patent Application WO 01/52541 of NDS Limited;    Article entitled “Using data mining to profile TV viewers” by William E. Spangler, Mordechai Gal-Or and Jerrold H. May, in Communications of the ACM, December 2003, Vol. 46, No. 12; and    Article entitled “Decision Tree Media” from www.DesignTaxi.com January 2008.